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Papers by soja soman

Research paper thumbnail of Development and evaluation of a simple and effective real time PCR assay for mitochondrial quantification in racing camels

Molecular and Cellular Probes, Oct 1, 2016

Research paper thumbnail of Uncovering Hidden Treasures: mapping morphological changes in the differentiation of human Mesenchymal Stem Cells to Osteoblasts using Deep Learning

Research paper thumbnail of Rapid and inexpensive process to fabricate paper based microfluidic devices using a cut and heat plastic lamination process

Lab on a Chip

Cut and heat microfluidic paper-based analytical devices (CH-microPADs) are simple-to-use, low-co... more Cut and heat microfluidic paper-based analytical devices (CH-microPADs) are simple-to-use, low-cost point-of-care testing platforms.

Research paper thumbnail of 3D Bioprinting of human Mesenchymal Stem Cells in a novel tunic decellularized ECM bioink for Cartilage Tissue Engineering

Research paper thumbnail of Dynamics of camel and human hemoglobin revealed by molecular simulations

Scientific Reports, 2022

Hemoglobin is one of the most widely studied proteins genetically, biochemically, and structurall... more Hemoglobin is one of the most widely studied proteins genetically, biochemically, and structurally. It is an oxygen carrying tetrameric protein that imparts the characteristic red color to blood. Each chain of hemoglobin harbors a heme group embedded in a hydrophobic pocket. Several studies have investigated structural variations present in mammalian hemoglobin and their functional implications. However, camel hemoglobin has not been thoroughly explored, especially from a structural perspective. Importantly, very little is known about how the heme group interacts with hemoglobin under varying conditions of osmolarity and temperature. Several experimental studies have indicated that the tense (T) state is more stable than the relaxed (R) state of hemoglobin under normal physiological conditions. Despite the fact that R state is less stable than the T state, no extensive structural dynamics studies have been performed to investigate global quaternary transitions of R state hemoglobin ...

Research paper thumbnail of Bioprinting of bioactive tissue scaffolds from ecologically-destructive fouling tunicates

Journal of Cleaner Production, 2022

Research paper thumbnail of Chimerism and central

Research Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian be... more Research Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian beta-defensin Apl_AvBD2 which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Defensins comprise a group of antimicrobial peptides, widely recognized as important elements of the innate immune system in both animals and plants. Cationicity, rather than the secondary structure, is believed to be the major factor defining the antimicrobial activity of defensins. To test this hypothesis and to improve the activity of the newly identified avian b-defensin Apl_AvBD2 by enhancing the cationicity, we performed in silico site directed mutagenesis, keeping the predicted secondary structure intact. Molecular dynamics (MD) simulation studies were done to predict the activity. Mutant proteins were made by in vitro site directed mutagenesis and recombinant protein expression, and tested for antimicrobial activity...

Research paper thumbnail of Progress in cardiovascular bioprinting

Artificial Organs, 2021

Cardiovascular disease has been the leading cause of death globally for the past 15 years. Follow... more Cardiovascular disease has been the leading cause of death globally for the past 15 years. Following a major cardiac disease episode, the ideal treatment would be the replacement of the damaged tissue, due to the limited regenerative capacity of cardiac tissues. However, we suffer from a chronic organ donor shortage which causes approximately 20 people to die each day on waiting to receive the organ. Bioprinting of tissues and organs can potentially alleviate this burden by fabricating low cost tissue and organ replacements for cardiac patients. Clinical adoption of bioprinting in cardiovascular medicine is currently limited by the lack of systematic demonstration of its effectiveness, high costs and the complexity of the workflow. Here, we give a concise review of progress in cardiovascular bioprinting and its components. We further discuss the challenges and future prospects of cardiovascular bioprinting in clinical applications.

Research paper thumbnail of Molecular insights into the interaction of hemorphin and its targets

Scientific Reports, 2019

Hemorphins are atypical endogenous opioid peptides produced by the cleavage of hemoglobin beta ch... more Hemorphins are atypical endogenous opioid peptides produced by the cleavage of hemoglobin beta chain. Several studies have reported the therapeutic potential of hemorphin in memory enhancement, blood regulation, and analgesia. However, the mode of interaction of hemorphin with its target remains largely elusive. The decapeptide LVV-hemorphin-7 is the most stable form of hemorphin. It binds with high affinity to mu-opioid receptors (MOR), angiotensin-converting enzyme (ACE) and insulin-regulated aminopeptidase (IRAP). In this study, computational methods were used extensively to elucidate the most likely binding pose of mammalian LVV-hemorphin-7 with the aforementioned proteins and to calculate the binding affinity. Additionally, alignment of mammalian hemorphin sequences showed that the hemorphin sequence of the camel harbors a variation – a Q > R substitution at position 8. This study also investigated the binding affinity and the interaction mechanism of camel LVV-hemorphin-7 w...

Research paper thumbnail of Perspectives on 3D Bioprinting of Peripheral Nerve Conduits

International Journal of Molecular Sciences, 2020

The peripheral nervous system controls the functions of sensation, movement and motor coordinatio... more The peripheral nervous system controls the functions of sensation, movement and motor coordination of the body. Peripheral nerves can get damaged easily by trauma or neurodegenerative diseases. The injury can cause a devastating effect on the affected individual and his aides. Treatment modalities include anti-inflammatory medications, physiotherapy, surgery, nerve grafting and rehabilitation. 3D bioprinted peripheral nerve conduits serve as nerve grafts to fill the gaps of severed nerve bodies. The application of induced pluripotent stem cells, its derivatives and bioprinting are important techniques that come in handy while making living peripheral nerve conduits. The design of nerve conduits and bioprinting require comprehensive information on neural architecture, type of injury, neural supporting cells, scaffold materials to use, neural growth factors to add and to streamline the mechanical properties of the conduit. This paper gives a perspective on the factors to consider whil...

Research paper thumbnail of Bioprinting of Human Neural Tissues Using a Sustainable Marine Tunicate-Derived Bioink for Translational Medicine Applications

International Journal of Bioprinting

Bioprinting of nervous tissue is a major challenge in the bioprinting field due to its soft consi... more Bioprinting of nervous tissue is a major challenge in the bioprinting field due to its soft consistency and complex architecture. The first step in efficient neural bioprinting is the design and optimization of printable bioinks which favor the growth and differentiation of neural tissues by providing the mechanophysiological properties of the native tissue microenvironment. However, till date, limited studies have been conducted to make tissue specific bioinks. Here, we report a novel bioink formulation specifically designed for bioprinting and differentiation of neural stem cells (NSCs) to peripheral neurons, using a marine tunicate-derived hydrogel and Matrigel. The formulation resulted in seamless bioprinting of NSCs with minimal processing time from bioink preparation to in vitro culture. The tissues exhibited excellent post-printing viability and cell proliferation along with a precise peripheral nerve morphology on in vitro differentiation. The cultured tissues showed signifi...

Research paper thumbnail of Molecular dynamics simulation studies and

Research paper thumbnail of 3D Printing of Complex Architected Metamaterial Structures by Simple Material Extrusion for Bone Tissue Engineering

Materials Today Communications

Research paper thumbnail of Applications of 3D Bioprinted-Induced Pluripotent Stem Cells in Healthcare

International Journal of Bioprinting

Induced pluripotent stem cell (iPSC) technology and advancements in three-dimensional (3D) biopri... more Induced pluripotent stem cell (iPSC) technology and advancements in three-dimensional (3D) bioprinting technology enable scientists to reprogram somatic cells to iPSCs and 3D print iPSC-derived organ constructs with native tissue architecture and function. iPSCs and iPSC-derived cells suspended in hydrogels (bioinks) allow to print tissues and organs for downstream medical applications. The bioprinted human tissues and organs are extremely valuable in regenerative medicine as bioprinting of autologous iPSC-derived organs eliminates the risk of immune rejection with organ transplants. Disease modeling and drug screening in bioprinted human tissues will give more precise information on disease mechanisms, drug efficacy, and drug toxicity than experimenting on animal models. Bioprinted iPSC-derived cancer tissues will aid in the study of early cancer development and precision oncology to discover patient-specific drugs. In this review, we present a brief summary of the combined use of ...

Research paper thumbnail of Discovery of Anas platyrhynchos avian β-defensin 2 (Apl_AvBD2) with antibacterial and chemotactic functions

Molecular Immunology, 2009

The cationic, cysteine-rich peptides called ␤-defensins play a major role in the innate immune re... more The cationic, cysteine-rich peptides called ␤-defensins play a major role in the innate immune response. Here, we describe the identification and characterization of the duck ␤-defensin-2 homologue, Anas platyrhynchos avian ␤-defensin 2 (Apl AvBD2). The 195 base pair open reading frame (ORF) of Apl AvBD2 has 83% identity with Gga AvBD2 (chicken) and 85% identity with Mga AvBD2 (turkey) at nucleotide level. The gene corresponding to the coding region is comprised of three exons and two introns in both Apl AvBD2 and Gga AvBD2. The predicted secondary structure of Apl AvBD2 has the classical "␤defensin core motif" formed by the ␤-sheet rich structure. Apart from mild expression in tissues like kidney, lung, brain, bursa of Fabricious and ovary, Apl AvBD2 mRNA show a very high level constitutive expression in bone marrow and spleen, indicating that it is a myeloid defensin. Purified recombinant Apl AvBD2 demonstrated in vitro antibacterial activity against both Gram-positive and Gram-negative bacteria, with a minimum bactericidal concentration (MBC) of 3.7 M against Micrococcus luteus NCIM 2871 and Escherichia coli NCIM 2685, and of 2.2 M against Reimerella anatipestifer. The immunomodulatory potential of Apl AvBD2 was shown by chemotaxis of DT-40 chicken B-lymphocytes. The widespread tissue distribution and the potent bactericidal and chemotactic activity make Apl AvBD2 an important molecule in the innate immune response in ducks. It may play a vital role in the immune response of these birds against bacterial and viral pathogens.

Research paper thumbnail of Functional characterization of the CC chemokine RANTES from Pekin duck ( Anas platyrhynchos

Developmental and Comparative Immunology, 2011

a b s t r a c t RANTES (Regulated upon Activation, Normal T-cell Expressed and Secreted) is a key... more a b s t r a c t RANTES (Regulated upon Activation, Normal T-cell Expressed and Secreted) is a key pro-inflammatory cytokine that belongs to the CC-group of chemokines. The present study was carried out to functionally characterize the previously identified RANTES homologue in domestic duck (GenBank Accession No. AY641435). Recombinant duck RANTES was expressed in Escherichia coli-based and HEK293T cellbased systems. A tRNA supplementation strategy was required to express the protein in E. coli due to the presence of rare codons. In biological assays using HEK293T cell-expressed protein, RANTES was found to mediate chemotaxis of DT-40 chicken B cells and primary duck splenocytes at a concentration of 0.505 g/ml (0.6 M). Immunostaining of the migrated splenocytes using anti-duck CD4 and CD8 monoclonal antibodies and subsequent flow cytometric analysis showed enhanced chemotaxis of CD8+ cells. The recombinant RANTES exhibited in vitro antiviral activity by inhibiting infection of chicken embryo fibroblast cells with duck enteritis virus (DEV) at the same concentration. The effect could be neutralized by rabbit anti-duck RANTES polyclonal serum. The mechanism seems to be direct on viral particles as evidenced by the need for co-incubation of RANTES with DEV prior to the infection for antiviral activity, and also by the enhanced binding of DEV to E. coli expressed purified RANTES on ELISA-based assays. Our results show that the duck RANTES has overlapping biological properties with its mammalian orthologue, and also has possible functional cross-reactivity with chicken immune cells indicated by the chemotaxis of DT-40 cells.

Research paper thumbnail of Immunomodulation by duck defensin, Apl_AvBD2: In vitro dendritic cell immunoreceptor (DCIR) mRNA suppression, and B and T-lymphocyte chemotaxis

Molecular Immunology, 2009

The present study analyzed the immunomodulatory potential of a newly identified duck ␤-defensin, ... more The present study analyzed the immunomodulatory potential of a newly identified duck ␤-defensin, Apl AvBD2. Recombinant Apl AvBD2 expressed in HEK293T cells induced a concentration dependent in vitro migration of duck splenocytes, and spleen B-and T-lymphocytes, which was specifically inhibited by anti-Apl AvBD2 polyclonal antibodies. Among the transcripts of 13 immunologically important genes analyzed in cultured splenocytes for the early immunomodulatory effect of Apl AvBD2, dendritic cell immunoreceptor (DCIR) mRNA was found to be significantly down-regulated. However, there were no major changes in the expression levels of transcripts for cell surface proteins (MHC I, MHC II 2 ␤chain, TCR-␤, TLR-7, DCAR, CD44, and CD58) and cytokines (IL-2, IFN-␥, RANTES, MIP-1␤-like and MCP-1 like chemokines). Our results reveal chemotactic and immunomodulatory properties of Apl AvBD2, two important functions that would help in employing this protein as a molecular adjuvant with avian vaccines.

Research paper thumbnail of Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian beta-defensin Apl_AvBD2

BMC Bioinformatics, 2010

Background: Defensins comprise a group of antimicrobial peptides, widely recognized as important ... more Background: Defensins comprise a group of antimicrobial peptides, widely recognized as important elements of the innate immune system in both animals and plants. Cationicity, rather than the secondary structure, is believed to be the major factor defining the antimicrobial activity of defensins. To test this hypothesis and to improve the activity of the newly identified avian β-defensin Apl_AvBD2 by enhancing the cationicity, we performed in silico site directed mutagenesis, keeping the predicted secondary structure intact. Molecular dynamics (MD) simulation studies were done to predict the activity. Mutant proteins were made by in vitro site directed mutagenesis and recombinant protein expression, and tested for antimicrobial activity to confirm the results obtained in MD simulation analysis.

Research paper thumbnail of Development and evaluation of a simple and effective real time PCR assay for mitochondrial quantification in racing camels

Molecular and Cellular Probes, Oct 1, 2016

Research paper thumbnail of Uncovering Hidden Treasures: mapping morphological changes in the differentiation of human Mesenchymal Stem Cells to Osteoblasts using Deep Learning

Research paper thumbnail of Rapid and inexpensive process to fabricate paper based microfluidic devices using a cut and heat plastic lamination process

Lab on a Chip

Cut and heat microfluidic paper-based analytical devices (CH-microPADs) are simple-to-use, low-co... more Cut and heat microfluidic paper-based analytical devices (CH-microPADs) are simple-to-use, low-cost point-of-care testing platforms.

Research paper thumbnail of 3D Bioprinting of human Mesenchymal Stem Cells in a novel tunic decellularized ECM bioink for Cartilage Tissue Engineering

Research paper thumbnail of Dynamics of camel and human hemoglobin revealed by molecular simulations

Scientific Reports, 2022

Hemoglobin is one of the most widely studied proteins genetically, biochemically, and structurall... more Hemoglobin is one of the most widely studied proteins genetically, biochemically, and structurally. It is an oxygen carrying tetrameric protein that imparts the characteristic red color to blood. Each chain of hemoglobin harbors a heme group embedded in a hydrophobic pocket. Several studies have investigated structural variations present in mammalian hemoglobin and their functional implications. However, camel hemoglobin has not been thoroughly explored, especially from a structural perspective. Importantly, very little is known about how the heme group interacts with hemoglobin under varying conditions of osmolarity and temperature. Several experimental studies have indicated that the tense (T) state is more stable than the relaxed (R) state of hemoglobin under normal physiological conditions. Despite the fact that R state is less stable than the T state, no extensive structural dynamics studies have been performed to investigate global quaternary transitions of R state hemoglobin ...

Research paper thumbnail of Bioprinting of bioactive tissue scaffolds from ecologically-destructive fouling tunicates

Journal of Cleaner Production, 2022

Research paper thumbnail of Chimerism and central

Research Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian be... more Research Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian beta-defensin Apl_AvBD2 which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Defensins comprise a group of antimicrobial peptides, widely recognized as important elements of the innate immune system in both animals and plants. Cationicity, rather than the secondary structure, is believed to be the major factor defining the antimicrobial activity of defensins. To test this hypothesis and to improve the activity of the newly identified avian b-defensin Apl_AvBD2 by enhancing the cationicity, we performed in silico site directed mutagenesis, keeping the predicted secondary structure intact. Molecular dynamics (MD) simulation studies were done to predict the activity. Mutant proteins were made by in vitro site directed mutagenesis and recombinant protein expression, and tested for antimicrobial activity...

Research paper thumbnail of Progress in cardiovascular bioprinting

Artificial Organs, 2021

Cardiovascular disease has been the leading cause of death globally for the past 15 years. Follow... more Cardiovascular disease has been the leading cause of death globally for the past 15 years. Following a major cardiac disease episode, the ideal treatment would be the replacement of the damaged tissue, due to the limited regenerative capacity of cardiac tissues. However, we suffer from a chronic organ donor shortage which causes approximately 20 people to die each day on waiting to receive the organ. Bioprinting of tissues and organs can potentially alleviate this burden by fabricating low cost tissue and organ replacements for cardiac patients. Clinical adoption of bioprinting in cardiovascular medicine is currently limited by the lack of systematic demonstration of its effectiveness, high costs and the complexity of the workflow. Here, we give a concise review of progress in cardiovascular bioprinting and its components. We further discuss the challenges and future prospects of cardiovascular bioprinting in clinical applications.

Research paper thumbnail of Molecular insights into the interaction of hemorphin and its targets

Scientific Reports, 2019

Hemorphins are atypical endogenous opioid peptides produced by the cleavage of hemoglobin beta ch... more Hemorphins are atypical endogenous opioid peptides produced by the cleavage of hemoglobin beta chain. Several studies have reported the therapeutic potential of hemorphin in memory enhancement, blood regulation, and analgesia. However, the mode of interaction of hemorphin with its target remains largely elusive. The decapeptide LVV-hemorphin-7 is the most stable form of hemorphin. It binds with high affinity to mu-opioid receptors (MOR), angiotensin-converting enzyme (ACE) and insulin-regulated aminopeptidase (IRAP). In this study, computational methods were used extensively to elucidate the most likely binding pose of mammalian LVV-hemorphin-7 with the aforementioned proteins and to calculate the binding affinity. Additionally, alignment of mammalian hemorphin sequences showed that the hemorphin sequence of the camel harbors a variation – a Q > R substitution at position 8. This study also investigated the binding affinity and the interaction mechanism of camel LVV-hemorphin-7 w...

Research paper thumbnail of Perspectives on 3D Bioprinting of Peripheral Nerve Conduits

International Journal of Molecular Sciences, 2020

The peripheral nervous system controls the functions of sensation, movement and motor coordinatio... more The peripheral nervous system controls the functions of sensation, movement and motor coordination of the body. Peripheral nerves can get damaged easily by trauma or neurodegenerative diseases. The injury can cause a devastating effect on the affected individual and his aides. Treatment modalities include anti-inflammatory medications, physiotherapy, surgery, nerve grafting and rehabilitation. 3D bioprinted peripheral nerve conduits serve as nerve grafts to fill the gaps of severed nerve bodies. The application of induced pluripotent stem cells, its derivatives and bioprinting are important techniques that come in handy while making living peripheral nerve conduits. The design of nerve conduits and bioprinting require comprehensive information on neural architecture, type of injury, neural supporting cells, scaffold materials to use, neural growth factors to add and to streamline the mechanical properties of the conduit. This paper gives a perspective on the factors to consider whil...

Research paper thumbnail of Bioprinting of Human Neural Tissues Using a Sustainable Marine Tunicate-Derived Bioink for Translational Medicine Applications

International Journal of Bioprinting

Bioprinting of nervous tissue is a major challenge in the bioprinting field due to its soft consi... more Bioprinting of nervous tissue is a major challenge in the bioprinting field due to its soft consistency and complex architecture. The first step in efficient neural bioprinting is the design and optimization of printable bioinks which favor the growth and differentiation of neural tissues by providing the mechanophysiological properties of the native tissue microenvironment. However, till date, limited studies have been conducted to make tissue specific bioinks. Here, we report a novel bioink formulation specifically designed for bioprinting and differentiation of neural stem cells (NSCs) to peripheral neurons, using a marine tunicate-derived hydrogel and Matrigel. The formulation resulted in seamless bioprinting of NSCs with minimal processing time from bioink preparation to in vitro culture. The tissues exhibited excellent post-printing viability and cell proliferation along with a precise peripheral nerve morphology on in vitro differentiation. The cultured tissues showed signifi...

Research paper thumbnail of Molecular dynamics simulation studies and

Research paper thumbnail of 3D Printing of Complex Architected Metamaterial Structures by Simple Material Extrusion for Bone Tissue Engineering

Materials Today Communications

Research paper thumbnail of Applications of 3D Bioprinted-Induced Pluripotent Stem Cells in Healthcare

International Journal of Bioprinting

Induced pluripotent stem cell (iPSC) technology and advancements in three-dimensional (3D) biopri... more Induced pluripotent stem cell (iPSC) technology and advancements in three-dimensional (3D) bioprinting technology enable scientists to reprogram somatic cells to iPSCs and 3D print iPSC-derived organ constructs with native tissue architecture and function. iPSCs and iPSC-derived cells suspended in hydrogels (bioinks) allow to print tissues and organs for downstream medical applications. The bioprinted human tissues and organs are extremely valuable in regenerative medicine as bioprinting of autologous iPSC-derived organs eliminates the risk of immune rejection with organ transplants. Disease modeling and drug screening in bioprinted human tissues will give more precise information on disease mechanisms, drug efficacy, and drug toxicity than experimenting on animal models. Bioprinted iPSC-derived cancer tissues will aid in the study of early cancer development and precision oncology to discover patient-specific drugs. In this review, we present a brief summary of the combined use of ...

Research paper thumbnail of Discovery of Anas platyrhynchos avian β-defensin 2 (Apl_AvBD2) with antibacterial and chemotactic functions

Molecular Immunology, 2009

The cationic, cysteine-rich peptides called ␤-defensins play a major role in the innate immune re... more The cationic, cysteine-rich peptides called ␤-defensins play a major role in the innate immune response. Here, we describe the identification and characterization of the duck ␤-defensin-2 homologue, Anas platyrhynchos avian ␤-defensin 2 (Apl AvBD2). The 195 base pair open reading frame (ORF) of Apl AvBD2 has 83% identity with Gga AvBD2 (chicken) and 85% identity with Mga AvBD2 (turkey) at nucleotide level. The gene corresponding to the coding region is comprised of three exons and two introns in both Apl AvBD2 and Gga AvBD2. The predicted secondary structure of Apl AvBD2 has the classical "␤defensin core motif" formed by the ␤-sheet rich structure. Apart from mild expression in tissues like kidney, lung, brain, bursa of Fabricious and ovary, Apl AvBD2 mRNA show a very high level constitutive expression in bone marrow and spleen, indicating that it is a myeloid defensin. Purified recombinant Apl AvBD2 demonstrated in vitro antibacterial activity against both Gram-positive and Gram-negative bacteria, with a minimum bactericidal concentration (MBC) of 3.7 M against Micrococcus luteus NCIM 2871 and Escherichia coli NCIM 2685, and of 2.2 M against Reimerella anatipestifer. The immunomodulatory potential of Apl AvBD2 was shown by chemotaxis of DT-40 chicken B-lymphocytes. The widespread tissue distribution and the potent bactericidal and chemotactic activity make Apl AvBD2 an important molecule in the innate immune response in ducks. It may play a vital role in the immune response of these birds against bacterial and viral pathogens.

Research paper thumbnail of Functional characterization of the CC chemokine RANTES from Pekin duck ( Anas platyrhynchos

Developmental and Comparative Immunology, 2011

a b s t r a c t RANTES (Regulated upon Activation, Normal T-cell Expressed and Secreted) is a key... more a b s t r a c t RANTES (Regulated upon Activation, Normal T-cell Expressed and Secreted) is a key pro-inflammatory cytokine that belongs to the CC-group of chemokines. The present study was carried out to functionally characterize the previously identified RANTES homologue in domestic duck (GenBank Accession No. AY641435). Recombinant duck RANTES was expressed in Escherichia coli-based and HEK293T cellbased systems. A tRNA supplementation strategy was required to express the protein in E. coli due to the presence of rare codons. In biological assays using HEK293T cell-expressed protein, RANTES was found to mediate chemotaxis of DT-40 chicken B cells and primary duck splenocytes at a concentration of 0.505 g/ml (0.6 M). Immunostaining of the migrated splenocytes using anti-duck CD4 and CD8 monoclonal antibodies and subsequent flow cytometric analysis showed enhanced chemotaxis of CD8+ cells. The recombinant RANTES exhibited in vitro antiviral activity by inhibiting infection of chicken embryo fibroblast cells with duck enteritis virus (DEV) at the same concentration. The effect could be neutralized by rabbit anti-duck RANTES polyclonal serum. The mechanism seems to be direct on viral particles as evidenced by the need for co-incubation of RANTES with DEV prior to the infection for antiviral activity, and also by the enhanced binding of DEV to E. coli expressed purified RANTES on ELISA-based assays. Our results show that the duck RANTES has overlapping biological properties with its mammalian orthologue, and also has possible functional cross-reactivity with chicken immune cells indicated by the chemotaxis of DT-40 cells.

Research paper thumbnail of Immunomodulation by duck defensin, Apl_AvBD2: In vitro dendritic cell immunoreceptor (DCIR) mRNA suppression, and B and T-lymphocyte chemotaxis

Molecular Immunology, 2009

The present study analyzed the immunomodulatory potential of a newly identified duck ␤-defensin, ... more The present study analyzed the immunomodulatory potential of a newly identified duck ␤-defensin, Apl AvBD2. Recombinant Apl AvBD2 expressed in HEK293T cells induced a concentration dependent in vitro migration of duck splenocytes, and spleen B-and T-lymphocytes, which was specifically inhibited by anti-Apl AvBD2 polyclonal antibodies. Among the transcripts of 13 immunologically important genes analyzed in cultured splenocytes for the early immunomodulatory effect of Apl AvBD2, dendritic cell immunoreceptor (DCIR) mRNA was found to be significantly down-regulated. However, there were no major changes in the expression levels of transcripts for cell surface proteins (MHC I, MHC II 2 ␤chain, TCR-␤, TLR-7, DCAR, CD44, and CD58) and cytokines (IL-2, IFN-␥, RANTES, MIP-1␤-like and MCP-1 like chemokines). Our results reveal chemotactic and immunomodulatory properties of Apl AvBD2, two important functions that would help in employing this protein as a molecular adjuvant with avian vaccines.

Research paper thumbnail of Molecular dynamics simulation studies and in vitro site directed mutagenesis of avian beta-defensin Apl_AvBD2

BMC Bioinformatics, 2010

Background: Defensins comprise a group of antimicrobial peptides, widely recognized as important ... more Background: Defensins comprise a group of antimicrobial peptides, widely recognized as important elements of the innate immune system in both animals and plants. Cationicity, rather than the secondary structure, is believed to be the major factor defining the antimicrobial activity of defensins. To test this hypothesis and to improve the activity of the newly identified avian β-defensin Apl_AvBD2 by enhancing the cationicity, we performed in silico site directed mutagenesis, keeping the predicted secondary structure intact. Molecular dynamics (MD) simulation studies were done to predict the activity. Mutant proteins were made by in vitro site directed mutagenesis and recombinant protein expression, and tested for antimicrobial activity to confirm the results obtained in MD simulation analysis.